Olopatadine Hydrochloride

Background The latest international joint guideline supports the use of second-generation H1 antihistamines(sgAHs) as the first-line treatment for chronic spontaneous urticaria. Objective To compare the efficacy and safety of various sgAHs on Chronic Spontaneous Urticaria (CSU) through direct or indirect evidence. Methods PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched for randomized controlled trials of various types of sgAHs in the treatment of CSU up to March 2025.For efficacy, the primary outcome was the change from baseline in the total symptom score, while the secondary outcomes were pruritus score and wheal score.For safety, the total numbers of all withdrawals due to adverse events and common adverse effects were extracted for each treatment, which included central nervous system side effects and anticholinergic side effects. Results We identified and included 24 randomized clinical trials (RCTs) involving 5172 patients. Ebastine ranked first in the total symptom score(standardized mean difference(SMD) -2.80[95% confidence interval(CI):-5.12 to -0.47]) and pruritus score (SMD -1.10[95%CI: -2.06 to -0.13]), while olopatadine ranked first in the wheal score (SMD -0.84 [95%CI :-1.37 to -0.32]).Bepotastine besilate had a significantly lower incidence of somnolence in adverse events (odds ratio(OR) 0.15[95%CI: 0.03 to 0.69]) than other sgAHs. Conclusions Both ebastine and olopatadine showed promising efficacy and no significant differences were found in acceptability and safety compared with placebo. There are no meaningful differences in safety risks between different second-generation antihistamines. Keywords: second-generation antihistamines; Chronic urticaria; Total symptom score; Adverse events; Network meta-analysis.